The post reads: “On July 1, 2018, 3 year old Ava-May Littleboy tragically lost her life after a bouncy castle exploded on Gorleston beach, Norfolk.

“Her family would like to kindly ask for donations to help fund a child’s bench in memory of Ava that will be put in her local park of Somersham, Suffolk.”

Superintendent Roger Wiltshire of Norfolk Police said: “We were called to a report of an inflatable trampoline apparently bursting on Gorleston beach, following a call to the ambulance service.

“I’m very sad to report that a three-year-old girl was injured in that incident and subsequently died in hospital.

“The witnesses report a loud bang before the incident but we don’t know at this stage what caused the trampoline to apparently burst and that’s the purpose of the investigation that we will be undertaking over the next day or so.”

He said the inflatable was designed to be used by one person, and she was the only person on it at the time.

Police said experts from as far afield as Wales were assisting with the investigation, and a cordon is likely to remain in place until Tuesday evening.

Supt Wiltshire said the incident was “just unimaginable”.

One witness claimed in a post on social media that the inflatable had “exploded” and that the child was thrown several feet into the air, the Evening Standard reported.

Politicians have called for a temporary ban on the giant inflatables after a police investigation was announced.

Robert Halfon, the Conservative MP for Harlow – where seven-year-old Summer Grant was killed after a gust of wind lifted a bouncy castle from its moorings in 2016 – tweeted: “Another horrific tragedy after the horrific tragedy in #Harlow in 2016.

“Clearly there needs to be a serious review into regulations around bouncy castles. Just awful,” he said.